Specific Gravity and Hydrometer Help!

[mazdaspeed]

Ok so yesterday I went out and bought a coralife hydrometer. I was getting a little scared with my instant ocean one because the little float thing in the needle had popped out twice and had to be put back in and I just wasn't sure how accurate it was being. The coralife made some pretty big claims about how accurate it was and my lfs used it on all there tanks and everything they've ever had there has always looked amazing.
So long story kinda short when I measured my s/g with my instant ocean one it has been telling me for over a month now that my tank is at after taking temp into consideration 1.025 or about 35ppm. Now today I used my new coralife one and it is telling me my s/g is 1.021 or about 28ppm. So what the heck do I do!!!
I haven't lost anything in my tank and I have a beautiful torch coral and a frogspawn along with inverts and two fish that are all doing amazing, should I just say screw it and leave things a lone, should I take my water somewhere and have it tested maybe with a refractometer to see how accurate I am, or should I go with the coralife and work at raising my s/g up to the 1.025 like I thought it was. Please help as I'm a bit worried... Oh as a secondary note all my other numbers are perfect couldn't ask for better including calcium and alk so I have no other problems there.

 

[tuningvis]

please do not freak out about the level you are at ... not a huge deal..

a lil fluctuation(sp) is okay ... and wont kill everything in your tank

 

[reefnut]

I would double check the s/g with a refractometer. This way you know exactly where it is. Your LFS may be about to test it for you.
If it is in fact 1.021, add some salt to your top off water. SLOWLY bring it up until it's where you want it.

 

[dory36]

We have the same hydrometer and it consistently runs about 1.021. I have my lfs check all my levels once a week and they get 1.025 with their refractometer.